Glass and mirror sheets or plates have traditionally been transported in wooden crates padded with materials such as paper or polystyrene foam. A layer of padding is put in the bottom of the crate, the sheets of glass are stacked on top of the padding, then a second layer of padding is put on top of the glass, and the top of the crate is nailed on. This system provides good protection for the glass sheets during handling, but is wasteful of materials and manpower.
In light of this, it has become more common for glass sheets to be shipped without wooden crates or padding in units known as glass packs. A glass pack consists of a stack of glass sheets or mirrors held together as a single unit by strapping or the like. The glass sheets are held tightly together so that the unit may be treated as a single thick plate of glass. A glass pack does not include additional padding or packaging around the edges. Thus, the glass pack must be handled carefully so that the edges of the glass sheets are protected from chipping and cracking during handling. It is also necessary to protect the lifting equipment and personnel from the sharp edges of the glass.
In the prior art, it has been common to use web slings, typically of nylon or polyester, for lifting and handling glass packs. However, this is often done with the web in direct contact with the glass edges. This results in cutting and premature wear of the slings, possibly culminating in failure of a sling during lifting of a glass pack. Such an occurrence can result in breakage of the glass and possible injury to personnel.
Consequently, from an examination of the prior art, it is apparent that a need exists for a sling system which enables the safe and effective handling of glass packs, glass sheets, or similar objects. The system must protect the glass from damage, and also be durable, reliable, and easy to use. The present invention overcomes the shortcomings associated with the prior art handling devices, and provides a substantial advance in the art.